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Confused .... y=xx 
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#1
Feb1908, 11:08 AM

P: 20

The problem is to graph this equation y=xx.
From what I understand of absolute values, this x would be positive. If it is positive then y=0 and there would be no points to graph. Is there something that I am missing? The question is worth 4 points, so I can't see the answer just being 0. Thanks for any suggestions. 


#2
Feb1908, 11:16 AM

Mentor
P: 15,167

What happens when x is negative?



#3
Feb1908, 11:22 AM

P: 88

What I was taught to do when dealing with absolute value, is to rewrite the equation so that the absolute value is isolated, then find the 2 equations.
so you'll have: x=xy y=o and also: x=x+y 2x=y 


#4
Feb1908, 11:47 AM

P: 20

Confused .... y=xx
The absolute value of x would be x. But I remember with inequalities there are 2 possible answers with absolute value (,+). From what you are explaining it sounds like that is what you are saying to do, use both possible values. Then I would graph by beginning with y at 0 and continue by substituting values into 2x=y? That seems to make sense to me. Thank you both for your help!



#5
Feb1908, 11:53 AM

P: 641

Also just try plugging in some numbers:
For 2 > Y = 2  2 = 0 For 2  > Y = 2 2 = 2 2 = 4 see? So for negatives you have Y = 2X, X<0 


#6
Feb1908, 01:33 PM

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P: 2,822

Solve or graph y = x  x.
If x>0, then y = x  x, meaning y=0. If x<0, then y = x  (x) [ notice those are parentheses, not absolute value notation symbols ], meaning y = x + x = 2x. 


#7
Feb1908, 02:15 PM

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Thanks
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#8
Feb1908, 05:04 PM

P: 88

I rearranged the formula to isolate the absolute value.



#9
Feb1908, 06:59 PM

P: 20

Wow, you guys couldn't have made it any more clear for me. Thanks alot!



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